Methods: In this diagnostic study mathematical formulas associated with a polynomial function and a beta function was used to reconstruct the dental arch forms of 20 adolescents with normal occlusion. CBPs were marked on every tooth present in each maxillary and mandibular model (second molar to second molar) using an orthodontic bracket positioning gauge. A coordinate Measuring Machine (CMM) was used to record the coordinates of each CBP (x, y).Then curveExpert software was operated to obtain the best beta function and associated curve fitted to the arch. A polynomial 4th degree function and curve was obtained for same models using CBPs only on central incisors, canines and second molars. Curves for each model were compared using statistical values including correlation coefficient, sum of residuals and root mean square(RMS).
Results: The statistical values for two curves fitted to each dental model had insignificant differences. There were no differences between maxillary and mandibular dental arches in this issue.
Conclusions: : Both 4th degree polynomial equation constructed by 6CBPs and beta- function can be used for curve fitting to normal arch forms.